Keeps watch over (6)
I believe the answer is:
guards
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">keeps watch over</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for guards that I've seen before include "Protection" , "troops" , "They keep watch" , "Defends" , "Watches over and protects" .)